NEW YORK - Mopping the floor or cleaning the bathroom - these are tasks some may dread. But Arnold Nelson sees them differently.

"Every day I wake up, I thank the Lord and I smile every day. Anytime you see me, I've got a smile," Nelson said.

After spending most of his life addicted to drugs - and three years in prison for a related offense - Nelson had had enough.

He finally got help in 2009 and soon after, was given a chance to start over with the Carter Burden Network.

The non-profit organization hired him as a custodian for their East Harlem location through a welfare to work program aimed at helping often overlooked populations learn work skills and find work.

"The bad days are behind me. That's what I call a bad day, the years behind me. Any other day isn't bad because I wake up sober, happy, and with a smile," Nelson said.

More than 10 years sober, today Nelson is the maintenance supervisor for the Leonard Covello Senior Program. 

He is the center’s keeper of the keys - 60 of them, to be exact. 

To him, they symbolize trust and responsibility - something few would have given him a decade ago. 

"I couldn't ask for a more dedicated employee. He is just - whenever there is a crisis, whenever there is a spill, he'll get out any one of his 60 keys and know exactly what to do with it, and with the greatest spirit! Always making someone smile," said William Dionne, Executive Director of Carter Burden Network.

Nelson gets in most mornings around 5:30 a.m. and punches out well beyond his eight hours. 

He first checks the whole building - then sweeps and mops the floors, and fixes whatever is needed. 

And even on his days off he sometimes stops in to make sure everything is running smoothly for the center's 150 seniors. 

While Nelson says he's "just doing his job," bosses say his story of redemption and his positive attitude is an inspiration to everyone he meets. And just as special, they say, are the bonds he has built with the seniors. 

"Anyone you ask in the center here about Arnold they're going to say the same thing - Arnold is the best," said Santos Aguirre, a member of the Leonard Covello Senior Program.

As for retirement, the 64-year-old says it couldn't be further from his mind. 

"Oh! When I retire, that's when the keys get too heavy and that's going to be a long time! I don't have no plans yet," Nelson said.

So, for overcoming obstacles and finding success, friendship and trust, Arnold Nelson is our New Yorker of the Week.